Summary of Stock Activity (Details) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2017 USD ($) Years $ / shares shares	Dec. 31, 2016 USD ($) Years $ / shares shares
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Options outstanding | shares	156,310	236,385
Options granted | shares	4,555
Options exercised | shares	(84,630)
Options outstanding weighted average exercise price | $ / shares	$ 25.82	$ 25.35
Options outstanding weighted average exercise price - Granted | $ / shares	37.55
Options outstanding weighted average exercise price - modification | $ / shares	30.21
Options outstanding weighted average exercise price - Exercised | $ / shares	$ 25.13
Options outstanding weighted average remaining term | Years	5.5	6.1
Options outstanding weighted average grant date fair value	$ 1,595	$ 2,440
Options granted weighted average grant date fair value	75
Options modified weighted average grant date fair value	(137)
Options exercised weighted average grant date fair value	$ (783)
Options exercisable at September 30, 2017 | shares	114,020
Options exerciseable weighted average exercise price | $ / shares	$ 23.83
Options exerciseable weighted average remaining term | Years	4.7
Options exerciseable weighted average grant date fair value	$ 1,010
Options vested during nine months ended September 30, 2017 | shares	26,839
Options vested weighted average grant date fair value	$ 223